****DNA COMPUTING****

INTRODUCTION:

“A computer is nothing but a device or a machine which manipulates data according to the set of instructions given to it.” This definition is well known to all of us. Now a days, computer has its own significance as a multi applicable device.

BIRTH OF COMPUTERS:

The birth of computers goes back to many decades. A computer has lion’s share in the development of this whole universe. Right from the discrete components to the silicon chip based microprocessors; the technological improvement in the field of computers is outstanding.

BIOPROCESSOR:

Computer processor manufacturer are furiously trying to manufacture a processor more compact, faster and capable. To achieve it, an inventive technological research on “DNA computers” is going to provide a path. It is a computer so powerful it can simulate the most complex and mysterious aspects of the universe.

EVOLUTION OF DNA COMPUTERS:

The unique combination of biotechnology and computer science made it possible to have a computer, embedded on DNA. The existence of it will lead to have an enormous speed of operation and billion times data storage capacity in a computer. Leonard Adleman, from The University of Southern California, invented this technology, resulting in the simpler, faster and integrate computation and execution of the task.

BIO-MEDICAL PRINCIPLES:

By using the biomedical principles of DNA and its bio medical structural advantages, DNA computer will have more number of parallel data processing buses to provide more executable instructions to be executed at the same unit time interval. Also the constructional alignments of it will provide more number of memory locations in a single DNA, for more memory storage.

CURRENT ROLE OF DNA-COMPUTERS:

As of now, the DNA computer can only perform rudimentary functions, and it has no practical applications. The device can check whether a list of zeros and ones has an even number of ones. The computer cannot count how many ones are in a list, since it has a finite memory and the number of ones might exceed its memory size. Also, it can only answer yes or no to a question. It can't, for example, correct a misspelled word

TECHNOLOGIES:

The race sees three new technologies - the optical supercomputer - which uses the tremendous speed of light, the quantum supercomputer uses qubits (instead of the standard binary ones and zeroes) and last but not the least the DNA Computer – the most strangest of all which uses DNA. Now let us delve into the not so distant past to glean an idea of how DNA Computing came about.

From Microsoft to "Bio-soft" :

In the early 1990's mathematician and biologist Leonard Adelman, the father of DNA Computing became fascinated by the parallels between DNA and computing technology. Computers use binary code which manipulates data as zeros and ones while genes consist of information encoded as strings of the four nucleotides that make up DNA: adenine(A),cytosine(C),guanine(G) and thymine(T)

Potential Technological Applications:

· Combinatorial Optimization Problems

· Hamiltonian path problem (HPP

· Solve the Boolean formula satisfactory problem (SAT)

· Performs other mathematical calculations.

Programmable Nanofabrication:

Biology uses algorithmically controlled growth processes to produce nanoscale and hierarchically structured materials with properties far beyond the capability of today’s human technology.

DNA SELF ASSEMBLY:

DNA self-assembly could be used in a variety of ways to solve this problem: molecular components (e.g., AND, OR, and NOT gates, crossbars, routing elements) could be chemically attached to DNA tiles at specific chemical moieties, and subsequent self-assembly would proceed to place the tiles (and hence circuit elements) into the appropriate locations.

Using self-assembly to direct the construction of circuits as large and complex as those found in modern microprocessors is daunting.Regular gate arrays, such as those used in cellular automata and field programmable gate arrays (FPGAs), are another natural target for algorithmic self-assembly of circuits.

DNA IN PARALLEL COMPUTING:

DNA is modified biochemically by a variety of enzymes. Enzymes work to cut DNA or paste them, or as copiers. In a test tube, enzymes do not work sequentially on one DNA at a time but rather many copies of the enzyme can work on many DNA molecules simultaneously thus allowing parallel computing.

Acrobatic Feats of Computation:

DNA computers are today being programmed to react in the presence of a toxin such as a cancer when they are embedded in a cell. When the DNA Computer detects the toxin it will glow enabling early detection and will carry out the necessary computations to save lives.

FUTURE OF DNA COMPUTERS:

Since the DNA computer uses molecular reactions, it is best suited for problems that require direct processing of molecules. In the future it will most certainly be used in

the study of logic, encryption, genetic programming, algorithms, language systems and maybe even lots of other interesting things that haven’t been developed yet.

ILLUSTRATION:

An airline serves six cities, but not all of the cities have nonstop service with each other. What is the largest group of cities that all have nonstop service with one another? The answer is four (cities 2, 3, 4, and 5).

Computers now solve such problems by trial and error. But if hundreds of cities were involved, a conventional computer would require years to find the answer. A DNA computer, on the other hand, tests all possible answers simultaneously, offering the prospect of much speedier solutions.